Taking care of multiple aquariums can be tough, but there are things you can do to make maintenance go a little more smoothly. For one, coordinate all of your water changes in the same day. There is no point to do water changes over multiple days. You can also do all the algae scraping, topping off, equipment maintenance that same day too. Just be sure to not cross contaminate your aquariums with water from the others. You could transmit nuisance algae, parasites, and other harmful stuff from one tanks to the next.
That said, if doing all of those tasks on the same day chews up too much time, you could break it up so that water changes are on one day and other maintenance activities fall on another.